In every dynamic sport, motion combined with resistance produces power. For example, in tennis, the server winds up his upper body as his lower body resists and then the player whips the racket through impact. The wound up, stored up energy is released through the shoulders and into the racket by the connection of the shoulders to the end of the racket.
The same is true of other racket sports as well as club and bat sports. In each of these sports, a large amount of resistance and motion is generated throughout the body which in turn is transferred to the racket, club, or bat. To optimize the larger, stronger muscles of the body, a proper kinetic link must be maintained between the motion generated by those muscles and the racket, club, or bat. Generally, the player's only contact with the racket, club, or bat is the hand or hands of the user.
A perfect example of this principal can be witnessed in a golf swing. The golfer contacts a club with both of his hands at one end of the shaft. Then, in a long, continuous motion, the golfer develops a series of resisting forces working against each other to build up a tensioning at the top of the swing. This tensioning is then released, and together with the fluid motion of the golfer's body, this release of tension generates the club head speed which is imparted to the ball.
In a golf swing, the golfer begins with his club at a stationary position behind the ball, and through a series of motions brings that club head back and then forward again to impact the ball and swing through the ball. Where the club head faces at impact will determine the flight of the ball and the spin put on that ball. If the club faces squarely to its path of movement at impact, the ball will not only take off on that path but will also continue straight in that direction, given on-center contact without any influence of wind. If the club head is facing to the left of its path, the ball will curve to the left of that directional path. If it faces to the right of this path, the ball will curve to the right. Thus, to maintain consistency in shots, it is imperative that a golfer consistently return his club head to the ball so that the club face is in the desired orientation. This desired orientation is generally the orientation the club head has before the beginning of the swing. The problem with returning the club head to this proper position is the body undergoes a large amount of movement during the swing.
To maximize club head speed as well as consistency, it is necessary to do what golfers call "swing through the ball". This simply means that the club head must be brought up and back along a swing path and returned along that path. During this movement, the club head face does not remain square with the target, but instead resembles the movement of an opening and closing door. Thus, at the beginning portions of the swing of a right-hander, the club head face points more and more to the right of the target. Once the club head reaches the top of the swing, it begins back down and closes this angle back to square at impact. On the follow-through, or portion after impact with the ball, the club head faces more and more left of the target. To effectively perform this movement, all that is required is a swinging of the club about a pivot point. Any twisting or unnatural contortions of the wrists or body during the swing could cause the club head to return along the wrong swing path or could cause the club face not to return to the ball in a squared fashion.
Generating the maximum club head speed while swinging through the ball requires the pivot point be as far away from the club head as is physically possible. In the golf swing, that means the pivot point is the left shoulder. By creating the pivot at the left shoulder, the golfer creates an arc upon which the club head must travel which includes the length of the left arm as well as the length of the club. By moving the left arm and the club together as a unit, the club head may travel along this arc and generate its maximum speed at the bottom of the swing. However, maintaining a straight line with the left ann and the club throughout the backswing causes the swing to be stiff and uncomfortable, and limits the amount the golfer can bring the club head back. This problem is resolved by having the wrists break (called a "wrist cock") during the backswing and return to the original position by impact. Additional club head speed is generated by having the wrist cock at the top of the swing by creating a second pivot point at the hands or end. of the club such that the club head may generate speed from the action of the wrists. The wrist cock also makes the swing a more fluid motion.
The problem with the use of these two pivot points is that a player must start from the position shown in FIG. 1, where the club shaft and the left arm form a straight line, and move to the position in FIG. 2, where the club head and the left arm form basically an acute angle, and back to a position as is shown in FIG. 3 where the left arm and club form a straight line once again.
To properly perform a wrist cock, the wrist must move along certain planes. In describing movement of the wrists, the following terms will be used: extension, flexion, abduction, and adduction. Flexion and extension are caused by pivoting the hand about a transverse axis of the wrist which lies parallel to the back of the wrist; flexion being the movement of the palm forward toward the forearm, extension being the movement of the back of the hand toward the forearm. If a plane is defined parallel to the transverse axis and parallel to the back of the hand, abduction and adduction are the movement of the hand back and forth in that plane; abduction being the movement of the hand toward the little finger, and adduction being the movement of the hand toward the thumb.
Most amateurs have a breakdown somewhere in their swing and do not return to the position shown in FIG. 3 at impact. A common mistake among right-handed amateurs is allowing the stronger right hand to take over in the swing and force the left hand to collapse into an extension or flexion. As a golfer first begins playing, this is the relaxed and easiest form of the swing. However, by allowing the left hand to collapse, the kinetic link between the left shoulder and the club head is broken and the full radial arc between the shoulder and the club head is not maintained. The club therefore impacts the ball in an orientation other than the optimal, and a slice, hook, duff, or other unwanted result occurs.
To correctly get into the position of FIG. 3, a golfer must have the back of his left hand substantially parallel to and substantially in the same plane as the back of his wrist. This means that if any extension or flexion of the left wrist occurs when the golfer moves from the position in FIG. 1 to the position in FIG. 2, that flexion or extension must be reversed such that the wrist and hand are back into the planar position as is shown in FIG. 3. To accurately time any such reversal on a consistent basis is difficult, if not impossible, to do.
To avoid extension or flexion of the wrists, it is preferred that right-handed golfers maintain the back of their left hand in a planar position with the back of the left wrist during the entire swing. The wrist cock is therefore performed by adduction and abduction of the left wrist.
Holding the wrists in this proper position takes strength. However, for most amateurs the flexors (the muscles of the forearm which are contracted when the hand extends into flexion) and the extensors (the muscles of the forearm which are contracted when the wrist extends into extension) are not properly developed; therefore, the golfer is unable to hold the wrist properly in position throughout the swing. Deadlocking the wrist to the club is not enough. A proper swing requires that the grip be loose, but firm, and that the wrist be capable of adduction and abduction. The muscles of the lower arm must be strong enough to prevent the wrist from moving into flexion or extension during the swing, yet relaxed enough when holding this position to allow for a loose grip so that free swinging of the club may occur.
An additional problem amateur golfers encounter is developing the proper angle between the forearms and the club. As viewed in FIG. 1, the left forearm and the club form a straight line. However, when that view is from behind the golfer, or from the left in FIG. 1, the forearm and club form an obtuse angle. This juncture is not straight because it is nearly impossible to grip a club and bend the wrist to align with the shaft. Instead, in the natural grip, the hands extend downward from the shoulders and grip the club, which extends outward to the ball. Several studies indicate the proper angle between a line extending from the club underneath the left forearm and a line extending parallel to the forearm should be about 19.degree.. This, the obtuse angle formed between the left forearm and the club would be approximately 161.degree.. This angle has been found to be the most ergonomically correct angle, in that it is the most comfortable and therefore promotes correct return to the same position. Amateur golfers often extend the club too far away from the body, or hold it too close to the body, making the angle more or less than this ergonomic optimum. Therefore, the golfer finds it more difficult to return his club along the swing path because he is working against the natural movement of his wrists.
There is a need in the art for a device which develops proper muscle, tendon, and nerve memory for a golfer to position his hands correctly throughout a swing and which additionally gives exercise to the forearm muscles so that the golfer may hold the club in that position when removing the device. There is also a need for a device which promotes proper positioning of the hands relative to a golf club.